Using Mash selection sets removes random placement

[Parmenides]

When using scatter under Distribute is great for random placement of objects on the surface of a mesh  but if you add a selection set of the faces, you lose the random placement of the distributed objects.  Can't see a reason why this would be shouldn't be possible. 

In this image I created a selection set of the bottom half of faces but it ignores the scatter. Is it necessary that scatter and selection sets are mutually exclusive? 

[sepu6]

You can't really do that if you think about it. Explain to me how that would work?
When you create a set you are telling which pts exactly you want. If you do not want all of them just pick random pts then. You can not combine both of those options. What you could do is delete random pts from the set if you want something more random. 

[Parmenides]

I don't see why it wouldn't work. Say for example you have a sphere with 100 faces. You scatter 20 among those 100 points in the array. When you have a selection set of the bottom 50 faces you scatter the 20 among those faces in the array.  If you take the sphere and delete the non-set faces, you can scatter easily among the 50 faces.  That is what I ended up doing. I made a copy of the sphere, deleted faces, scattered on it and hid the partial sphere. Worked great, just a clumsy solution. 

[mspeer · Accepted solution]

Hi!

Sure, technically this would be possible, but this method is simply not implemented.

If you use a Selection Set, the only distribution method that uses this set is "Component Selection Set", so only this single method supports Selection Sets.

You can't use "Scatter" or any other method with a Selection Set.

If you want you can add a feature request here at Maya Ideas:
https://forums.autodesk.com/t5/maya-ideas/idb-p/968